At 10:58 PM +0100 1/1/02, Isaac OLEG SIMANOT wrote:
>As I understand what you said here it is an oil based varnish that you buff
>before applying a new coat of finishing (may be black French polishes on
>this ?)
French polish, so called because the technique was apparently first
used in France as "Vernis Jacques", is a solution of lac in spirit.
It contains no oil. There are many different qualities of lac
depending on the amount of wax removed, the decoloring etc. What is
sold with the name "French Polish" is generally a less expensive
variety containing a certain amount of the natural wax from the
bodies of the lac beetle that are used to make the shellac.
>Am I correct, and if so, why do you use 'rubber' ? I thought it was with
>foams or cotton that we can buff this kind of finish.
>Or does rubber mean something else ?
"Rubber" is a technical term that refers to a (roughly mango-shaped)
lump of folded sheet wadding covered in a cloth of cotton or linen of
a texture suitable for the stage of the work in progress. A more
open texture will be used for the main "bodying" rubbers and a finer
texture for finishing rubbers. Different hardnesses of rubber will
also be used at different stages.
>I had sometime good results on a refinishing with a cellulosic French polish
>that could be use on an existent finish (oil based) assuming the precedent
>was decontaminated, buffed and clean.
If all you want is a shiny finish, anything goes. If you want the
original clear figure of the wood to shine through and give depth to
the finish, there is no alternative to remove the old finish and
start from the bare wood. One of the reasons I hate polyester (and
there are many!) is that it gives no depth and richness. It is just
a thick coat of bluish plastic and in my opinion the most disgusting
finish. As to cellulose, whatever it's quality, I would never use it
again. Even the acid-catalysed varieties never go hard and a real
"glass finish" in impossible.
>
>But I don't know how to have black French polishing. What kind of tint do
>you use ?
You can buy ready-made black polish but this is based on "button
polish" which is a quality I do not normally use. Instead I use a
decolored clear polish or "special pale" to which I add "spirit
black". The color of this black is a very dark mauvish tint which
gives the effect of a very rich black. This is the dye that has
always been used for black finishes on pianos.
Oil ("white oil" or linseed oil) is used in French polishing but only
as a lubricant for the surface to enable the rubber to work smoothly.
The oil should remain on the surface and never be allowed to become
part of the bady. The finishing processes aim to remove all traces
of oil from the surface. Oil is traditionally used also on the bare
wood preparatory to polishing in order to enrich the figure of the
wood, but this also must be thoroughly removed from the surface of
the wood before work starts. Nevertheless it is normal for this oil
slowly to work up from the pores through the polish, and if the
furniture is not properly looked after it can form rough
incrustations on the surface. The use of oil has to be strictly
limited.
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